1. Field of the Invention
The present invention relates generally to the field of physical therapy aids and equipment. More specifically the present invention relates to a brace apparatus for applying selectable tension to a human joint such as a knee or an elbow, the tension pulling in the direction about which the limb closes around the joint. This tension serves either to progressively increase the range of joint movement or to provide resistance against which to exercise.
The apparatus includes a flexible tubular member sized to fit closely around a human limb and tension means in the form of an elastic strip connected to the member at either side of the joint. Tension selection means are provided for adjusting the magnitude of tension in the strip.
2. Description of the Prior Art
There have long been straps and other devices for supporting a human limb in a raised or angled position. One common example is the cast which holds a broken arm or leg in a bent position.
Malewicz, et al., U.S. Pat. No. 5,437,619, issued on Aug. 1, 1995, discloses a range-of-motion splint with an eccentric spring. Malewicz, et al., includes forearm collar, an upper arm collar, a first arm segment extending from adjacent the limb joint to engagement with the forearm collar and a second arm segment extending from adjacent the limb joint to engagement with the upper arm collar. A helical spring assembly pivotally interconnects the first and second arm segments and biases the arm segments and thus the nearer forearm and upper arm toward either an open position or a closed position. A key feature of Malewicz, et al., is that the helical spring is eccentrically mounted to give steady biasing throughout the arm range of movement at the joint. A problem with Malewicz, et al., is that the apparatus is relatively complex, heavy, costly and uncomfortable to wear.
Shirley, et al. U.S. Pat. No. 5,599,288, issued on Feb. 4, 1997, teaches an external ligament system. Shirley, et al., provides a brace for persons who have suffered damage to the ligaments of the knee for holding the tibia and the fibula against relative front to back motion while permitting the knee to bend. Shirley, et al. includes an elongated leg sheath and a pair of hinged external linkages. Each linkage is anchored to the sheath on one side of the leg, crosses over the leg and around a grooved roller on the opposing side and then crosses back again to the first side of the leg where it is anchored. A problem with Shirley, et al., is that it merely provides support, and offers no elastic tension as resistance to exercise against.
Fischer, et al., U.S. Pat. No. 5,352,190, issued on Oct. 4, 1994, reveals a knee brace. Fischer, et al., includes a first cuff fitted to the leg above the knee and a second cuff fitted to the leg below the knee, bendable linkages interconnecting the cuffs along the leg, and a hydraulic or pneumatic force applying mechanism extending between the cuffs. The force applying mechanism, which may be a hydraulic cylinder, either forces the knee into a bent position or into an unbent position, or bends and unbends the knee in a continuous cycle. Alternatively Fischer, et al., can be used to retain the knee in a fixed position to protect an injured joint. Problems with Fischer, et al., are that it is complex, heavy and expensive and does not, in its intended form, provide selectable resistance to joint movement for therapeutic exercise.
Tetreault, U.S. Pat. No. 4,875,677, issued on Oct. 24, 1989, discloses a lead arm strap for baseball hitters. The arm strap includes a first cuff which is fitted snugly around the forearm and a second cuff which is similarly fitted around the upper arm. Elastic straps joined at their ends to cuff buckles interconnect the cuffs along the inside of the arm, and bias the forearm and upper arm into a right angle relationship. Tetreault retains the arm in the proper hitting stance. A problem with Tetreault if used for physical therapy is that it produces tension only where the arm is extended beyond a ninety degree bend, and thus would produce incomplete exercise of the joint. Another problem is that no provision is made for changing the magnitude of tension resistance for progression in strength and arm flexibility and for different patients and conditions.
Other potentially relevant references are Lychou, U.S. Pat. No. 1,510,408, issued on Sep. 30, 1924 for a knee brace; Guedel, U.S. Pat. No. 3,698,389, issued on Oct. 17, 1972, for an elbow locking device; Labnels, U.S. Pat. No. 4,220,148, issued on Sep. 2, 1980 for a knee stabilizer; Senn, et al., U.S. Pat. No. 4,492,227, issued on Jan. 8, 1985, for an elastic knee bandage; Townsend, et al., U.S. Pat. No. 4,899,735, issued on Feb. 13, 1990 for a torsion bar splint for the forearm; and Hammersly, U.S. Pat. No. 5,472,410, issued on Dec. 5, 1995 for an adjustable flexion and extension joint orthoses.
It is thus an object of the present invention to provide a physical therapy limb brace apparatus which engages the limb on either side of a joint and which biases the joint toward a closed position.
It is another object of the present invention to provide such a brace apparatus which applies biasing tension which is readily adjustable to provide a progression of increased pull throughout treatment and to provide different tension ranges for different patients having differing conditions.
It is still another object of the present invention to provide such a brace apparatus which is easily fitted to and removed from a patient, and is light weight and comfortable.
It is finally an object of the present invention to provide such a brace apparatus which is simple in construction and is very inexpensive to manufacture.